Abstract
The failure mechanism of two commercial light-emitting diode (LED)-based spotlights with GU10 form factor is analyzed. Through component testing and comparison to nominal values as well as to simulations, it is found that the cause of both device failures is related to damaged components within the drive circuits rather than the LEDs themselves. Both LED heads work as normal when connected to an external direct current (DC) source. The results show that the lack of light output of one spotlight is related to the open circuit caused by damaged resistors and inductors in its drive circuit, while the flickering of the other is related to the malfunction of the integrated circuit providing constant current output. Therefore, improving the quality of the LED drive circuits is considered the most effective way for manufacturers to reduce catastrophic failures of LED spotlights.
Highlights
We have examined several failed commercial light-emitting diode (LED) spotlights and here report results from two such samples that showed two different common signs of catastrophic system failures
The LED head circuit of spotlight A starts to emit light at a direct current (DC) bias of 15 V, which corresponds to the minimum voltage across the LEDs in the integrated chip (IC) manual
A failure of the discrete components within the LED drive circuits is more likely than a damage of the LEDs themselves
Summary
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